This was easy to watch for me. I love things scientific as well as fantasy. The idea of a mechanical heart will be something in the future that will come true. We all have to daily charge ourselves whether it is technical or human nature. Temporary artificial hearts are already existing but not like this story depicted. The story was tragic in the beginning but everything came out... well you would have to watch it to see it. I loved how the storyline started with a tragedy to become such a beautiful storyline. This was kind of different for me. I have watched another KDrama that was similar but not human. I hope most will see this and know that our hearts are the most important thing that makes our bodies work. Your eyes are the window of your soul called life! I hope you enjoy this drama as much as I did. Thank you to all that made this drama series possible. I think the two main leads which I am researching now are to see more from them.